FRANKFURT/HELSINKI, Sept 26 (Reuters) - Finnish power utility Fortum will launch an 8.05 billion-euro ($9.5 billion) takeover bid for Uniper, the power stations operator and energy trading business partly-owned by German utility E.ON, it said on Tuesday.

It will offer 22 euros per share in cash, the primary aim being to acquire for 3.76 billion euros E.ON’s remaining 46.65 percent stake in Uniper, which was demerged from E.ON last year.

Uniper, with total sales of around 67 billion euros in 2016, operates roughly 40 gigawatts of power plants in Europe and Russia. It has hydroelectric, coal- and gas-fired plants as well as stakes in gas pipelines, liquefied natural gas terminals and nuclear plants across Europe, plus energy trading operations.

“This investment will strengthen the position of both companies to advance Europe’s energy transition. I believe that all stakeholders will benefit,” Fortum Chief Executive Pekka Lundmark told Reuters by phone.

But sources close to the matter have said that Fortum is mainly interested in Uniper’s hydropower plants and interests in Swedish nuclear power stations and has already been working with a partner that might take on Uniper’s coal-fired plants.

Following media reports on the proposed deal, Fortum and E.ON confirmed last week that they were in advanced talks over Uniper.

E.ON cannot sell its own stake before 2018, as this would trigger a hefty tax payment, and therefore it has the right to tender its own Uniper stake for the same price early next year.

If it opts not to, Fortum can sell to E.ON any Uniper shares by then already acquired and, on top, would get compensation from E.ON that amounts to at least 20 percent of the equity value of its Uniper stake, or 752 million euros.

Under German takeover rules, Fortum has to make a bid for the whole of Uniper as E.ON’s stake is above a critical 30 percent hurdle. The offer is unconditional on a minimum acceptance level.

DIALOGUE

Although Fortum tried to acquire the whole group already in July, Lundmark vowed that the company was not planning a takeover, or restructuring, this time.

“This deal has been signed with E.ON, and it automatically leads to the tender offer. We are totally satisfied with the E.ON stake, we are not targeting a control or a merger.”

“Financially, the investment alone is very justified...This is significant, when thinking of our own ability to pay dividends.” Uniper chief executive Klaus Schaefer told Reuters on Monday he viewed Fortum’s approach as hostile, saw no strategic fit and voiced doubts about how Fortum would fund a deal.

Lundmark regretted that he didn’t have time to discuss with Uniper before media reports on the deal forced Fortum and E.ON to go public with it last week.

“I understand him (Schaefer) very well... But since we apparently are becoming a major shareholder in the company, I hope we can start a good dialogue.”

“We are not hostile at all. We intend to be a long-term investor and we take our responsibility very seriously,” Lundmark said, adding that Fortum had no intention to push for forced redundancies at Uniper, or to change its corporate seat from Dusseldorf.

Uniper published a press release after the news, saying its management board would analyse and assess the offer.

Fortum said its bid of 22 euros a share offered a 36 percent premium to the price that prevailed before speculation on a potential transaction surfaced in May.

State-controlled Fortum is focused on carbon-free power generation, mainly in the Nordic region and Russia, and has been looking for a deal since selling its power distribution grids for 9.3 billion euros in 2014 and 2015.